@Override
 public boolean equals(Object obj) {
   if (this == obj) return true;
   if (obj == null) return false;
   if (getClass() != obj.getClass()) return false;
   PPNPrivacyPreferenceTreeModel other = (PPNPrivacyPreferenceTreeModel) obj;
   if (affectedCtxId == null) {
     if (other.affectedCtxId != null) return false;
   } else if (!affectedCtxId.equals(other.affectedCtxId)) return false;
   if (myContextType == null) {
     if (other.myContextType != null) return false;
   } else if (!myContextType.equals(other.myContextType)) return false;
   if (myPrivacyType != other.myPrivacyType) return false;
   if (pref == null) {
     if (other.pref != null) return false;
   } else if (!pref.equals(other.pref)) return false;
   if (requestor == null) {
     if (other.requestor != null) return false;
   } else if (!requestor.equals(other.requestor)) return false;
   return true;
 }